Net Natural Increase

Net natural increase is the difference between births and deaths. Along with domestic net migration and immigration, it is one of three primary components of population change. The crude rate of net natural increase is calculated by dividing net natural increase by an estimate of population. The rate is not adjusted for differences in the age composition.

Net natural increase is presented on Arizona Indicators since 1970 for the United States, Arizona, and the 15 Arizona counties.

Visualization Notes:

Net natural increase — the difference between the numbers of births and deaths — is cyclical, mostly due to a decrease in the number of births during economic recessions when some people postpone having children. Nationally and in Arizona, net natural increase peaked in 2007. The decrease between 2007 and 2011 was a stunning 35 percent in Arizona and 23 percent nationally. The larger decline in Arizona likely results from the state’s more severe recession and from the implementation of the “employer sanctions law” at the beginning of 2008. The law caused nearly 100,000 undocumented immigrants (who are young with a high birth rate) to leave the state during the first year of the law.

In 2012, net natural increase fell a little further in Arizona; data are not yet available nationally. However, the figure rose in Maricopa County but feel sharply in Pima County.

Visualization Notes:

Net natural increase per 1,000 residents was 5.7 in Arizona; the national figure is not yet available. The number of deaths was greater than the number of births — net natural decrease — in Gila, La Paz, Mohave and Yavapai counties, which have high shares of older residents. In contrast, net natural increase per 1,000 residents exceeded 7.5 in Santa Cruz and Yuma counties, which have a youthful population. The figure was nearly as high in Maricopa County, but was well below the state average in Pima County.

Visualization Notes:

Nationally and in Arizona, net natural increase per 1,000 residents has exhibited considerable cyclicality and a slow downward trend since 1970. The 2011 figure is the lowest of the last four decades nationally and in Arizona, largely the result of the long and deep recession followed by a weak economic recovery that caused the number of births to decline. The 2012 figure in Arizona was marginally lower than in the prior year.